In Sim City, your residents leave if you run the place poorly. In real life Chicago, half of all parents want to. It’s hard to think of a more biting metric. The biggest problem is that many people can’t afford to.
Expect to see the media ask this question again in places like Bridgeport, Cleveland, Detroit, and Flint, where, even if there were great leadership, it will be hard to turn police and schools around. Meanwhile, expect a 'great sorting' as people move to where they have hope for their kids. That's what drove most families to America in the first place.